Human skin and scalp become soiled due to its contact with the surrounding environment and from sebum, sweat, and so on. The soiling of skin and/or scalp causes them to have a dirty feel, and an unattractive appearance and/or smell. Such soiling of skin/scalp may cause unhealthiness, such as skin dryness. Unhealthy skin including dry skin has a less tight arrangement of stratum corneum cell layer, and tends to exfoliate more than a healthy moisture-balanced skin does. Such soiling of scalp may cause dandruff too. The soiling of the skin/scalp necessitates cleansing/shampooing with frequent regularity.
Assessing condition, especially cleanness and/or healthiness of skin/scalp is of interest in order to understand the impact of various factors including the impact of cleansing and/or shampooing. Thus, there is a need therefore for providing a method for assessing cleanness and/or healthiness of skin and/or scalp.
Furthermore, assessing dandruff condition of scalp is also of interest in order to understand the impact of various factors including the impact of shampooing and/or scalp care compositions. Thus there is also a need for providing a method for assessing dandruff condition of scalp.